Metal Impurities in Pharmaceuticals and Dietary Supplements - Implementing ICP-MS for USP ⟨232⟩ and Prop 65

The United States Pharmacopeia (USP) proposed general chapter 232 is the intended replacement for the old USP 231. Covering the range of active pharmaceutical ingredients for foods and dietary supplements will necessitate the inclusion of many elements. In order to meet this need and the growing list of products, technology used in the modem testing lab has been employed. Inductively coupled plasma mass spectrometry (ICP-MS) is an ideal choice for meeting these needs, with the ability to determine most of the elements in the periodic: table and a wide dynamic range, spanning part-per-trillion to part-per-million levels. This range means that trace contaminants as well as nutritionally significant elements can be measured during the same analysis. The only limitation of ICP-MS is that samples have to be in a liquid form, which necessitates digesting solid samples, which adds time and introduces the possibility of contamination. Microwave digestion is the perfect compliment to ICP-MS, ensuring rapid, clean digestions with no analyte loss. This work demonstrates a sample preparation procedure and analysis scheme which not only complies with the new proposed standards, but will take the modern analytical laboratory into the next decade. The combination of the Multiwave (TM) 3000 microwave digestion oven and the NexION (R) 300 ICP-MS, a new generation of ICP-MS instrumentation, is ideal for the analysis of pharmaceutical and dietary supplements.